Black Ghost Knife 22/27cm
Black Ghost Knife 22/27cm (Apteronotus albifrons) is a larger, impressive specimen of the classic Black Ghost Knife Fish, already around 22–27cm and ready for a spacious display aquarium. With its smooth, blade‑like body, ghostly black colour and graceful swimming style, this Black Ghost Knife Fish is best suited to experienced aquarists with a large, well‑filtered tank and suitable tank mates.
Size and Lifespan
- Current size: approximately 22–27cm
- Potential adult size: can reach around 40–50cm in a suitably large aquarium
- Lifespan: with good care, Black Ghost Knife Fish can live for many years
Black Ghost Knife 22/27cm – Tank Requirements
- Recommended tank size: a large aquarium (4ft+ in length, bigger is better) for a single Black Ghost Knife 22/27cm, with more space as it approaches full size
- Filtration: strong, reliable filtration with good biological capacity and gentle flow in resting areas
- Décor: plenty of hiding places – caves, pipes, driftwood and plants help the fish feel secure
- Lighting: relatively dim or shaded areas, as the Black Ghost Knife Fish is naturally more active at night
Water Parameters (Guide Only)
- Temperature: around 24–27°C
- pH: roughly 6.5–7.5
- Hardness: soft to moderately hard water
- Ammonia & Nitrite: 0 ppm
- Nitrate: kept low with regular water changes
Feeding Black Ghost Knife Fish
- Suitable foods:
- Frozen or live bloodworms
- Brine shrimp
- Blackworms
- Small prawns or shrimp pieces
- Quality sinking carnivore pellets or sticks
Behaviour and Temperament
- Personality: shy to semi‑bold, often hiding during the day and exploring more at night
- Temperament: usually peaceful, but may become stressed or aggressive if crowded or kept with fin‑nippers
- Activity: glides along the bottom and mid‑levels, weaving in and out of décor
Tank Mates for Black Ghost Knife 22/27cm
- Large enough not to be seen as food by a growing Black Ghost Knife Fish
- Peaceful to semi‑aggressive, but not persistent fin‑nippers
- Comfortable in similar water parameters and temperature
Important Notes
- Not suitable for small aquariums – this Black Ghost Knife 22/27cm will need a large tank as it grows.
- Sensitive to poor water quality – strong filtration and regular maintenance are essential.
- Provide plenty of hiding spots so your Black Ghost Knife Fish feels secure and settles in well.
Black Ghost Knife 22/27cm



